Margarito Flores and his twin brother Pedro anxiously huddled in a lavish bathroom in South Zapopan, Mexico, as they prepared to call Joaquin "El Chapo" Guzman to discuss a shipment of heroin they had just received.

As Margarito paced, Pedro pressed the record button on his audiotape device and placed the call. Within minutes, the drug-dealing twins, who were now law enforcement informants, had evidence that would help lead to the capture and 2019 conviction of El Chapo, one of the world's most notorious drug kingpins.

"We felt pressing "record" was going to change ... the world of drug trafficking," Margarito Flores, 42, said during a recent interview with Reuters. "We felt that our cooperation was going to make a difference."

SON OF MEXICAN DRUG CARTEL KINGPIN 'EL CHAPO' EXTRADITED TO UNITED STATES

Flores, who once ran a multi-billion-dollar narcotics distribution network in the Chicago area with his brother, is now working on the other side of the law with Dynamic Police Training (DPT), an Illinois-based firm that trains narcotics investigators, agents and police officers across the nation.

His experience as a drug trafficker has given police and investigators an inside view into how major narcotics networks operate and helped shape best practices to dismantle their networks, according to officers who have taken the training courses offered by DPT.

What Flores brings to the table "is something I've never heard in 30 years of law enforcement training. It's a perspective that isn't available anywhere," said Clint Thulen, who works on a narcotics task force in the Chicago area. He declined to be more specific about the task force in the interest of those who are part of it.

Joaquin "El Chapo" Guzman

Joaquin "El Chapo" Guzman is escorted by soldiers during a presentation in Mexico City, on Jan. 8, 2016. (REUTERS/Tomas Bravo/File Photo)

Police investigators usually are not able to interview and glean information from people who work - or once worked - as high-level drug dealers, Thulen said.

"I don't know if there's anyone out there that could sit here today and understand the American drug trade, the Mexican drug trade, as I have," Flores said. "I live both sides of it from every aspect."

Between 2005 and 2008, Flores and his brother ran a distribution cell, one of the largest narcotic operations in Chicago's history, for the Beltran-Leyva and El Chapo's Sinaloa cartels. The operation received more than 1,500 kilograms of cocaine month, distributing it across the city and the country. They earned about $1.8 billion over that three-year span, according to federal court documents and the U.S Department of Justice.

After they were arrested and convicted, federal prosecutors credited the brothers with "unparalleled assistance" that helped form the basis of the government's strong case against El Chapo. For their cooperation, the twins were released in 2020, five years after they received a 14-year prison sentence from a federal judge and 12 years after they were initially taken into custody.

In September, Flores participated in his first training seminar at the Kane County Sheriff's Department, west of Chicago, where he spent a day with about 130 local, state and federal law enforcement personnel. Since then, Flores has participated in a handful of similar seminars around the United States.

"He's been there; he's done that. He knows how these organizations operate. He knows what is crucial in dismantling them," said Jeramy Ellison, who founded Dynamic Police Training in 2022 after serving as a narcotics officer in Texas and in the U.S. Army.

The focus of the seminar in the Chicago area was on the need for law enforcement to stop the flow of bulk U.S. currency, used to finance trafficking, into Mexico and other countries such as China and Colombia.

"That is what fuels the drug cartels. That is what fuels corruption and death in Mexico and in other countries," Flores said, noting that his organization exported $30 million to $50 million a month back to Mexico.

MEXICAN DRUG CARTEL KINGPIN 'EL CHAPO'S' SON ARRAIGNED ON FEDERAL TRAFFICKING CHARGES IN CHICAGO

One of the aspects of the training that caught Thulen's attention was how quickly Flores and his brother were able to change their modes of communications and transportation to evade law enforcement.

The training caused Thulen to pay particular attention to bulk loads in trailers, shipping containers and other vehicles with large cargo capacities, he said.

"You have to have the imagination to think a semi could be loaded a third full of contraband and currency," he added.

Flores, who was released from prison in 2020, said his training also stresses the need for local, state and federal law enforcement agencies to do a better job sharing information about ongoing investigations and suspects.

In addition, Flores gave insights on how he was able to move up from being a low-level street dealer in Chicago's Little Village neighborhood, where he grew up, to conducting international deals with El Chapo himself, Thulen said.

"By the time I was 17, I graduated. I had a degree in drug trafficking," said Flores, adding that he began in the drug business with his father when he was 7 years old.